How dichroic glass jewelry is made will determine a lot about how much wear you get out of it. Dichroic glass jewelry cabochons are made pretty much like an Oreo cookie. You have a clear glass top, a dichroic filling, and an art glass base. All three layers have importance. When viewing an auction look to see if the seller describes the item as "capped in crystal or clear glass", "fire-polished, "ground" and "annealed". All the steps are important. Although beautiful, matte finish dichroic pendants without the crystal cap glass will easily scratch and are more succeptible to breakage because they are typically thinner. Fire-polished means the item has usually been ground into shape and this step is needed to smooth and round the edges, remove scratches from the grinding process, and give the crystal cap a beautiful icy clear finish.. Annealed means the item has been heated to a  full fuseing temperature, and then held for 30 minutes or more around 900 degrees to give the glass molecules time to re-group. By doing this you add strength to the finished piece. If the photo is sharp, look at the edges and make sure no dichroic glass has leaked through the clear glass cap. Leaked dichroic will have a matte, unglossy look to it and will be very rough to the touch, it is after all essentially metal oxide. Also remember that dichroic glass transmits one color and reflects another, mix this with the fact that most computer monitors display colors slightly differently and it is almost impossible to photograph the finished piece. If you have any doubt on the color email the seller. Jewelry bails for these products come in nickel, sterling silver plated and 18ct. gold plated, if you have a nickel allergy you might want to inquire on the bail content if it is not spelled out in the auction. Also look for the size of the item, if the size is not listed, or if the item is not photographed with a coin or something for reference email the seller.